Studies In Jain Astronomy Postvedang Prisiddhantik Indian Astronomy - Book Summary

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Book Title: Studies in Jain Astronomy Postvedang Prisiddhantik Indian Astronomy Author(s): Sajjan Singh Lishk, S. D. Sharma Publisher: Z_Kailashchandra_Shastri_Abhinandan_Granth_012048.pdf Catalog Link: https://jainqq.org/explore/212224/1

This paper, "Post-Vedānga Pre-Siddhāntic Indian Astronomy (Studies in Jaina Astronomy)," by Sajjan Singh Lishk and S. D. Sharma, aims to illuminate a historically neglected period in Indian astronomy. While Vedānga Jyotiṣa (Vedic astronomy) and the later Siddhantic astronomy are well-understood, the era bridging these two periods has remained a "forgotten chapter." The authors assert that their research, based on the mathematical analysis of astronomical texts found within Jaina canonical literature, fills this crucial gap. They also highlight the importance of examining Buddhistic texts and Hindu literature like the Purāṇas and Smṛtis for a complete understanding of this period.

The authors challenge the views of scholars like D. Pingree, who propose a Mesopotamian origin for ancient Indian astronomy. They argue that this perspective overlooks the wealth of indigenous Indian knowledge, particularly from Jaina sources.

Key Arguments and Findings:

The "Dark Period": The paper identifies a significant gap in the history of Indian astronomy between the Vedānga Jyotiṣa period (around the 14th century BC) and the Siddhantic astronomy period (3rd/4th century AD). This period, estimated to be around 1500 years, is considered a "dark period" due to a lack of focused research.
Jaina Canonical Literature as a Source: The authors emphasize that Jaina canonical texts like Sūrya Prajñapti and Jambūdvipa Prajñapti contain vast astronomical knowledge from this "dark period." Their research has focused on mathematically analyzing this data, particularly from pre-Aryabhatian Jaina astronomy.
Challenging Western Perceptions: The paper addresses the tendency of Western scholars to attribute Indian scientific advancements to borrowings from Greece. The authors suggest that historical factors, including the colonial agenda to demoralize Indian scholarship and the lack of easily presentable physical evidence comparable to Egyptian or Mesopotamian civilizations, have led to a devaluation of indigenous Indian achievements.
Specific Astronomical Contributions of Jaina Astronomy:
- Units: Jaina astronomy exhibits a transition from trigesimal (thirty-fold) to sexagesimal systems for time units. They standardized the yojana and defined relationships between different types of yojanas. The zodiacal circumference was graduated in various time-based units, including time-degrees, days of a lunar sidereal revolution, muhūrtas (48-minute periods), and finally in solar days.
- Cosmography: Jainas aimed for a scientific formulation of the real world. Their concept of two Suns and two Moons was used for specific calculations. The dimensions of Mount Meru suggest an understanding of astronomical constants, particularly the obliquity of the ecliptic. The statement that the Moon is eighty yojanas higher than the Sun is interpreted not as vertical height but as a measure of celestial latitude.
- Sciatherics (Shadow Measurement): Jainas accurately measured time based on shadow lengths using gnomons, allowing them to determine the time of day directly. They also used shadow lengths to determine seasons, with the Summer Solstice being precisely measured.
- Kinematics: They understood the concept of declination in solar and lunar motions, though they didn't express it algebraically. They also compared the relative velocity of Venus with animal speeds and identified vithis (lanes) of Venus, implying a concept of geocentric latitudinal motion. These studies are seen as parallel to Seleucid and Mesopotamian planetary ephemerides.
- Calendar: The quinquennial cycle from Vedānga Jyotiṣa continued, but with different solstitial points. Jaina astronomers also conceived of other planetary cycles, such as those of Jupiter and Saturn. They utilized the 3:2 ratio of maximum and minimum day lengths, which, when analyzed using Bernoulli's theorem, corresponds to a latitude near Ujjain.
- Cycles of Eclipses: Jaina cycles for lunar and solar eclipses (42-eclipse months and 48-eclipse years respectively) were based on observations of periodic color repetitions and were independent of foreign influences like the Chaldean Saros or Metonic cycles.
- Lunar Occultations: The Jaina concept of lunar conjunction with a nakṣatra implies a positional understanding within the lunar zodiac.
- Measurement of Celestial Distances: Celestial angular distances were measured in yojanas, relating them to projected distances on Earth, reflecting an understanding of Earth's geometry.
- Observation of Celestial Phenomena: Jaina astronomers were keen observers, accurately measuring time via shadows, observing lunar occultations, determining solstices, studying Venus's heliacal combustion, determining the Moon's latitude, and observing the shapes and star counts of nakṣatras. Their eclipse cycles, based on color observations of Rāhu (shadow causing eclipse), and their classification of planets and nakṣatras demonstrate skilled observation.
- Astronomical Instruments: Besides the gnomon, instruments like clepsydras (water clocks) and star clocks were likely used. Descriptions of water clepsydras exist in the Viṣṇu Purāṇa and the Jaina work Jyotiṣa Karaṇḍaka.

Conclusion of the Authors:

The authors conclude that their research into the pre-Aryabhatian Jaina school of astronomy has opened new avenues for understanding the development of Siddhantic astronomy. They believe their findings necessitate a re-evaluation of claims that Indian astronomy is solely of external origin, particularly challenging D. Pingree's views on Mesopotamian influences. The paper suggests that Jaina astronomy played a significant role in bridging the gap between early Vedic astronomy and the later Siddhantic traditions.